Three former State Police lieutenants were indicted on additional charges Friday in an ongoing state probe into overtime abuse at a now-defunct unit that previously patrolled the Massachusetts Turnpike, according to the attorney general’s office.

A Suffolk grand jury returned additional indictments Friday against David Wilson, a 58-year-old Charlton resident; John Giulino, a 68-year-old Lanesborough resident; and David Keefe, a 53-year-old from Norfolk. They are alleged to have stolen thousands of dollars through claiming bogus overtime in 2015, according to the attorney general’s office.

Wilson, Giulino, and Keefe were charged Friday with one count each of larceny over $250 by a single scheme, procurement fraud, and public employee standards of conduct violation, prosecutors said.